Packard Forum Index » Pre-War (1899-1942)

Sticky valves would fit the symptoms for sure...after it got warmed up and the valves well lubed they might free up and smooth out.

Still wondering about that number one missing and still running smooth. That's a Packard for ya :)

I must have missed the point that the engine rebuild was done 30 years ago, and not run much since! That's key information and yes, surely the problem could be sticking valves though it's just as likely that its rust on the stems as varnish. Regardless, you have a good chance of having it clear up by just running the engine enough, aided perhaps by judicious use of "snake oil".

Hey, Thanks for the compliment.

Valve work on these cars is done under the fenders by removing the splasher shields. With electromatic the cylinder head is also a chore. The hood must be removed as well. The Packard MoCo sold a tool that screwed into the spark plug holes for lifting the head off. These can be made from used spark plugs or long metric bolts.

Anyway, The pitting is caused by rust, and sludge collects in the pitting which then hardens under heat soak to form varnish. When the motor is started the varnish combines with whatever other forms of dirt is in the guides and acts like a wedge that seizes the valve. In petroleum engineering glossaries varnish is defined as heat hardended sludges.

These varnishes can form very quickly in motors that do not reach full operating temperatures sufficient to boil off sludges while running and this explains the trailer show cars with brand new engines that run like crap because the valves are sticking.

Another really should have is a thermostat. Given that these old blocks run warmer and are thinner than new a 160F should be sufficient.

As to oils, I really like 10w-30, but if the ever popular 15w-40 is desired then use that with a quart of Rislone.

Good luck

The hood must be removed as well.

Tim's explanation on valve stem varnish is a good one. Though I wouldn't call it fun, the cylinder head on a 1941 senior can be removed without removing the hood. I leave the thermostat gooseneck and cylinder head heater valve on the head as hand-holds as I don't care to trust the puny 10mm spark plug threads to bear the weight, as many of them have been weakened by overzealous plug tightening over the years.

JT120: Thanks for the article on vacuum. It is great! I did see my mechanic use it, and he showed me the needle going like crazy, but I doubt that he will know that much detail as the article mentions!

Tim and all:

First, a word of THANKS, and my progress report:

We had found cil 1 to be the problem, with no compression there due to open valves. As suggested by Tim, we had a sticky valve problem. We found water marks from the radiator hose down the engine neck and down to spark plug 1, so what apparently happened (theory only) is that due to a not-tight spark plug, some water got in and created some rust in the valve stems.

We added quite a bit of fuel inyection cleaner to cil 1 and let the product soak for several hours. When we started the engine, it still missed a lot but work a little better. We did find some tiny rust particles or debris in the floor, under the exhaust pipe.

We repeated the process, with a lot of fuel injection cleaner to no. 1 piston, but adding some product to each cilynder, and let it soak for 24 hours. To my surprise, the engine this time started much better and missed only just a bit (not a constant no. 1 cilinder as before).

I never found Gumout but added a type of oily additive through the carb with the engine reving high. Lot's of smoke of course. This I guess means, because it showed a lot of improvement, that the 'major problem' was partially solved, but we might still have some sticky valves, partially working only.

Then we took oil off (oil pan cleanup is something I had done before and it was mint, as expected from a newly done engine)and following Tim's suggestion we added light oil, in our case, 4 quarts of 10-W30 and 3 quarts of 5-W20 plus some oil detergent. We let the car sit for a couple of days and this saturday I started it up and it works almost great! I drove it home (about 10 miles) and it really behaves well. I will be using it as is for a while before dumping the oil and adding thicker oil again.

So, car is runnning very decently now, and I am sure it will be improving as I use it.

So... thanks again for all the help!

Victor

Quote:Victor,
for including the '33 Eight Coupe Roadster, '37 Super Eight Touring Sedan and the '41 Lebaron Sport Brougham in the Packard Owner's Registry.

The '40 One-Ten Convertible Coupe and '56 Four Hundred Hardtop Coupe were already in the Registry under the Forum Name Victor.

Just leaves the '50 to round out the collection!

And glad that the '41 is running so much better now.

Mal:

Thanks for your words. I am very glad also.

Done... all of them registered. You sure do a great job on getting cars registered.

Victor

Quote:
I spoke too soon, here it is: Victor's '50 Super Deluxe Eight Victoria Convertible Coupe. again!

Reading this post gave me a wierd sense of deja vu - a 1941 180, misfire, except without the previous engine work. In my case #1 was dead - 0 compression. It turned out that the exhaust valve stems & guides were severely worn, letting the valve head "hang" off center & not close.
I did pull the head thru the fenderwell (that weren't no fun at all), but removed the fender completely when it was time to replace guides (& rings/rod bearings since I was in there.)
These big straight 8's have lots of mass & very low combustion pressure at idle, so it's not too unusual for a complete misfire to be overlooked until you put it under load.
After engine repairs, I found cranking compression tests to be around 70-80 psi. That's what you get with a 6.45 comp ratio. I assume psi will go up a little after seating the new rings.
In comparison, modern engines produce 150-220 psi compression- & won't run below 95 or so.